Advanced Custom Fields (ACF): Deserialization of Untrusted Data
CVE-2023-1196 is a high-severity deserialization of untrusted data vulnerability in Advanced Custom Fields (ACF) from Advanced Custom Fields (ACF®), with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists versions 5.12.5, 6.1.0 as the first without the flaw, so updating Advanced Custom Fields (ACF) to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.09% chance of exploitation within 30 days, higher than 66% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Advanced Custom Fields (ACF) to 5.12.5 or 6.1.0, whichever matches your release line, or a later version.
- Update Advanced Custom Fields (ACF) Pro to 5.12.5 or 6.1.0, whichever matches your release line, or a later version.
- Update Advanced Custom Fields to 5.12.5 or 6.1.0, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Advanced Custom Fields (ACF) | Advanced Custom Fields (ACF) | 5.0.0 up to, but not including, 5.12.5; 6.0.0 up to, but not including, 6.1.0 | 5.12.5, 6.1.0 |
| Advanced Custom Fields (ACF) Pro | Advanced Custom Fields (ACF) Pro | 5.0.0 up to, but not including, 5.12.5; 6.0.0 up to, but not including, 6.1.0 | 5.12.5, 6.1.0 |
| Advancedcustomfields | Advanced Custom Fields | 5.0.0 up to, but not including, 5.12.5; 6.0.0 up to, but not including, 6.1.0 | 5.12.5, 6.1.0 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.8 | High | NVD |
| CVSS 3.1 | 8.8 | High | CISA (ADP) |
Official description
The Advanced Custom Fields (ACF) Free and Pro WordPress plugins 6.x before 6.1.0 and 5.x before 5.12.5 unserialize user controllable data, which could allow users with a role of Contributor and above to perform PHP Object Injection when a suitable gadget is present.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Deserialization of Untrusted Data
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
How developers prevent this class of flaw
- If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
- When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
- Explicitly define a final object() to prevent deserialization.
More Deserialization of Untrusted Data vulnerabilities (CWE-502)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Technical write-ups (may include proof of concept)
- wpscan.com/vulnerability/8e5ec88e-0e66-44e4-bbf2-74155d849edeExploit, Third Party Advisory
- wpscan.com/vulnerability/cf376ca2-92f6-44ff-929a-ace809460a33Exploit, Third Party Advisory
Other vulnerabilities in Advanced Custom Fields (ACF)
- 7.5 High severity
Recent Deserialization of Untrusted Data vulnerabilities
- 7.2 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
- 7.8 High severity
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